This invention relates to a method and apparatus for reboiling a liquefied gas mixture comprising at least two components, of which one is more volatile than the other.
One example of a need in gas separation to reboil a liquefied gas mixture arises in the separation of air. For example, it is conventional in air separation processes that produce an argon product to cool by means of a stream of oxygen-enriched liquid air a condenser associated with a rectification column in which a crude argon product is produced. The oxygen-enriched liquid air is itself at least partially reboiled by condensing crude argon vapour. The resulting vapour is typically separated in another rectification column into oxygen-rich and nitrogen-rich fractions.
It is an aim of the present invention to provide a method and apparatus for reboiling a liquefied gas mixture which offers the possibility of reducing the thermodynamic work of separation required in a downstream rectification column.